class Car:
    """一次模拟汽车的简单尝试。"""
    def __init__(self,make,model,year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0
    def get_descriptive_name(self):
        long_name = f"{self.year} {self.make} {self.model}"
        return long_name.title()

    def read_odometer(self):
        print(f"This car has {self.odometer_reading} miles on it.")


    def update_odometer(self, mileage):
        if mileage >= self.odometer_reading:
            self.odometer_reading = mileage
        else:
            print("You can't roll back an odometer!")

    def increment_odometer(self, miles):
        self.odometer_reading += miles

class Battery:
    """一次模拟电动汽车电瓶的简单尝试。"""

    def __init__(self,battery_size=75):
        """初始化电瓶的属性。"""
        self.battery_size = battery_size

    def describe_battery(self):
        """打印一条描述电瓶容量的消息。"""
        print(f"This car has a {self.battery_size}-kWh battery.")

    def get_range(self):
        """打印一条消息，指出电瓶的续航里程。"""
        if self.battery_size == 75:
            range = 260
        elif self.battery_size == 100:
            range = 315

        print(f"This car can go about {range} miles on a full charge.")

class ElectricCar(Car):
    """电动汽车的独特之处。"""
    def __init__(self, make, model, year):
        """
        初始化父类的属性。
        再初始化电动汽车特有的属性。
        """
        super().__init__(make, model, year)
        self.battery = Battery()

my_tesla = ElectricCar('tesla','model s',2019)
print(my_tesla.get_descriptive_name())
my_tesla.battery.describe_battery()
my_tesla.battery.get_range()